We propose this SBIR effort to develop a unique three-dimensional (3D) surface imaging system for acquiring complete 3D surface profiles of a small animal undergoing in vivo optical tomography imaging procedures. The acquired 3D surface model of the small animal body provides accurate geometric boundary conditions for 3D reconstruction algorithms to produce precise 3D diffuse optical tomography (DOT) images. Advanced DOT algorithms require good a priori knowledge of the boundary geometry of the diffuse medium imaged in order to provide accurate forward models of light propagation within this medium. Original experimental DOT demonstrations for reconstructing absorbers, scatterers and fluorochromes all used phantoms or tissues that were confined to easily modeled geometries (such as a slab or a cylinder). In recent years several methods have been developed to model photon propagation through diffuse media with complex boundaries using finite solutions of the diffusion or transport equation (finite elements or differences) or more recently analytical methods based on the tangent-plane method. To fully exploit advantages of these sophisticated algorithms, accurate 3D boundary geometry of the subject must be extracted in a practical, real-time, and in vivo manner. To date, there is no known reported technique for extracting 3D dimensional boundaries with fully automated, accurate and real-time in vivo performance. We propose this SBIR project to address this pressing need in the small animal imaging community. The major innovation of this SBIR program is a new 3D imaging system design concept that will facilitate a speedy and convenient imaging configuration for acquiring a 3D model with complete 360-degree coverage of an animal body surface. Traditional 3D imaging methods of achieving complete surface coverage require either moving the image sensor or the animal body so that multiple 3D images from different viewing angles can be acquired. In in-vivo small animal optical imaging, the preferred way of performing image acquisitions is to obtain complete sets of images without moving either the camera or the animal. Specifically, our Phase I technical aims are listed below: Aim 1: Design and build functional prototype hardware of the proposed 3D imaging system; Aim 2: Develop 3D surface imaging reconstruction algorithms; Aim 3: Improve DOT algorithms to utilize the precise 3D geometric boundary data; Aim 4: Perform 3D and DOT imaging tests on small animal phantoms, assess prototype's performance; Aim 5: Develop a plan for integrating the 3D camera into a small animal DOT system in Phase II.